When molecules, atoms and ions accurately self-assemble into different forms in a solid and continuously repeat such forms in a long space, such pattern of self-assembly is referred to as “polymorph”. Different polymorphs have unique physical and chemical characteristics, including melting point, density, crystal morphology, solubility, and mechanical property.
In a method currently adopted by pharmaceutical industry to find suitable medicament, a slide with a protein film attached thereto is used as a substrate. Since this type of substrate has a special organic functional group formed thereon, it can be used to locate expecting medicament. According to some literatures, through evaporation coating, it is able to cause an organic material to form a monolayer on a substrate. In this case, the substrate is a semiconductor wafer having different crystallographic faces, bringing the molecules of the organic material to arrange in different orientations. In the conventional ways of finding polymorphs, different solvents are used to dissolve the organic material to prepare a mother liquor, and various crystallization processes, such as solution-cooling crystallization, anti-solvent crystallization or evaporative crystallization, can be used to prepare polymorphs from the mother liquor. However, according to the conventional crystallization processes, after the crystallization, steps such as filtering the mother liquor and drying are needed to thereby take more time to produce the polymorphs, and the prepared polymorphs could not be analyzed sooner to obtain the desired polymorphs. In brief, the conventional polymorph preparing and screening process is time-consuming and cost-waste.